pH‐sensitive crosslinked guar gum‐based superabsorbent hydrogels: Swelling response in simulated environments and water retention behavior in plant growth media

Abstract

Crosslinked guar gum-g-polyacrylate (cl-GG-g-PA) superabsorbent hydrogels were prepared to explore their potential as soil conditioners and carriers. The hydrogels were prepared by in situ grafting polymerization and crosslinking of acrylamide onto a natural GG followed by hydrolysis. Microwave-initiated synthesis under the chosen experimental conditions did not exhibit any significant improvement over the conventional technique. The optimization studies of various synthesis parameters, namely, monomer concentration, crosslinker concentration, initiator concentration, quantity of water per unit reaction mass, particle size of backbone, and concentration of alkali were performed. The hydrogels were characterized by wide-angle X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and solid-state 13 C-NMR spectroscopy. Swelling behavior of a candidate hydrogel [GG-superabsorbent polymer (SAP)] in response to external stimuli, namely, salt solutions, fertilizer solutions, temperature, and pH, was studied. The GG-SAP exhibited significant swelling in various environments. The effect of GG-SAP on water absorption and the retention characteristics of sandy loam soil and soil-less medium were also studied as a function of temperature and moisture tensions. The addition of GG-SAP significantly improved the moisture characteristics of plant growth media (both soil and soil-less), showing that it has tremendous potential for diverse applications in moisture stress agriculture.

Zeolite reinforced carboxymethyl cellulose‐Na+‐g‐cl‐poly(AAm) hydrogel composites with pH responsive phosphate release behavior

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Viscoelastic properties of borax loaded CMC‐g‐cl‐poly(AAm) hydrogel composites and their boron nutrient release behavior

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Composite Superabsorbent Hydrogel of Acrylic Copolymer and Eggshell: Effect of Biofiller Addition

“…In addition, water resources have been shown to be insufficient to produce food in many countries. Irrigation accounts for around 70% of the total anthropogenic water use, corresponding to 2,500 out of 3,800 km 3 . 1 In arid and semi-arid regions, where water supplies are limited, agricultural practices increase the water consumption resulting in the degradation of natural ecosystems.…”

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“…Despite being treated as a waste, many applications have been studied, mostly considering this material as a rich source of CaCO 3 . It has been proposed as an advanced and green alternative for a structural material in biocomposites based on epoxy formulations.…”